Cooling system for air cooled internal combustion engines



Nov. 25, 1958 E, STUMP 2,861,554

COOLING SYSTEM FOR AIR COOLED INTERNAL COMBUSTION ENGINES Filed March 22, 1956 2 Sheets-Sheet 1 INVENTOR EUGEN STUMP ATTORNEY S Nov. 25, 1958 E. STUMP 2,861,554

COOLING SYSTEM FOR AIR COOLED INTERNAL COMBUSTION ENGINES Filed March 22, 1956 2 Sheets-Sheet 2 INVENTOR EUGEN STU/VIP ATTORNEYS United States P t F COOLING SYSTEM FOR AIR COOLED INTERN COMBUSTION ENGINES I Eugen Stump, Stuttgart-Unterturkheim, Germany, assiguor to Daimler-Benz Aktiengesellschaft, Stuttgart- Unterlurkheim, Germany The present invention is an improvement over the cooling system for air cooled internal combustion engines disclosed in my copending application Serial No. 558,319 filed January 10, 1956, entitled Cooling System for Air Cooled Internal Combustion Engines.

Accordingly, the subject matter of the copending appli'-' cation is incorporated herein by reference.

The present invention, as also my aforementioned copending application, relates to a controllable cooling system for internal combustion engines, particularly aircooled internal combustion engines for motor vehicles in which the cooling air currents or streams, which flow. through the cooling jackets surrounding the individual cylinders, may be restricted orblockedrolf either partial! ly or completely, and in which .by-pass lines for the cooling air are provided, preferably between. the individual cooling jacket surrounding the cylinders, through which 'a largeror smaller portion of thecooling air may controllablyv flow or pass. Q

It is, therefore, a primary object of the present inven tion ,to provide an air-cooling system for internal combustion engines which, in particular, constitutes 'a simplification and further improvement of the control or ad'- jus'ting mechanism for the cooling system, of. air-cooled internal combustion engines and essentially consists in that a common shifting or control member is provided for. simultaneously controlling that portion '.of the cooling aiit which flows around the cylinders, on' the onehand, and that portion of the cooling air which flows through the bypass 'or short-circuit line, on'the other. Such an arrangement renders possible. the control oradjustmentfof the cooling effect or intensity by means of only a single control member. I s j Furthermore, such an arrangement also enables the use of a control arrangement having a great exactness and sensitivity in such 'a manner that an adjustable, uniform temperaturemay be obtained at the cylinders. This is possible in particular if a by-pass'or short-circuit line is provided through which the interior of the cooling jacket may be connected on both sides thereof with the air supply line or intake channell By means ofsuch a construction, it is possible to maintain an air circulation within the cooling air ducts or lines of the engine block or housing notwithstanding the complete blocking or shutting off of the air flow from the inlet line to the outlet line, whereby a temperature equalization between the hotter and cooler spots of the engine may be effected. l j

Accordingly, it is an object of the present invention to provide a control or adjustment mechanism forair cooling systems in connection with internal combustion engines which is simple inconstruction, easy to control'and effective to provide the desired control adjustment.

Another object of the present invention is to provide such a control mechanism for the cooling system of an air cooled internal combustion engine which enables the use ofonly one single control or adjusting member for each cylinder and associatedby-pass line;

' still another embodiment ofa control mechanism for an Patented Nov. 25, 1958 Another object of the present invention resides in the provision of an adjusting mechanism for use with the cooling system of an air cooled internal engine which at the same' time is easy to operate and offers a great sensitivity.

Another object of the present invention is to provide such a control or adjusting mechanism for the cooling system of an internal air cooled combustion engine which enables the equalization of temperatures between the hotter and cooler spots of the engine, notwithstanding the particular position to which the adjusting mechanism is set.

These and other features, objects and advantages of the present invention will become more obvious from the following description when taken in connection with the accompanying drawing which shows, for purposes of illustration only, several preferred embodiments in accordance with the present invention and wherein:

Figure 1 is a diagrammatic cross sectional view through a part of the engine block of a multi-cylinder internal combustion engine and through a part of the air cooling system thereof in accordance with the present invention; Figure 2 is a diagrammatic cross-sectional view similar to Figure 1 of another embodiment of an air cooling system for an air-cooled internal combustion engine in accordance with the present invention;

Figure 3 is a diagrammatic cross-sectional view through air cooled internal combustion engine in accordance with the present invention;

Figure 4 is a diagrammatic cross-sectional view through still another embodiment of the control mechanism for an air cooled internal combustion engine with the control valves located at the entrance to the'cooling jackets in accordance with the present invention; 7 p Figure 5 is a diagrammatic cross-sectional view similar to Figure '1, showing the interconnection of the air flow control valve members and venturi-shaped inlet and outlet openings to and from thecooling jacket in accordance with the present invention; L v

Figure 6 is a schematic partial .diagram showing thermostatic operation of the air fiow control valves in accordance with the present invention;

vention.

' Figure 7 is a schematic diagram showing operation of the air flow control valves of an air cooled internal combustion engine being responsive .to the engine throttle valve position according to the present invention; and

Figure 8 is a schematic diagram showing operation of the air flow control valves in an air cooled internal combustion engine being responsive to the fuel adjusting member of a fuel pump in accordance with the present in The construction of the cooling system in accordance with the present invention consists of cooling a jacket for each cylinder through which the cooling air currents may flow, a by-pass line formed between adjacent cooling-jackets of different cylinders, and a single control member, such as a butterfly valve or the like, to simultaneously control the relative amounts of cooling air pass-. ing through the respective cooling jacket and by-passiline or to establish circulation of the cooling airtherebetween when the connection with the outlet or discharge line is blocked. p

The adjusting or control member in accordance with the present invention is preferably made in such a 'way that it is adjustable to at least three positions, namely: 7

(a) To a closed position for warming up the engine in which the interior of the cooling jacket is connected with the by-pass or short-circuit line, while the passage from the cooling jacket and by-pass line toward the outside or outlet line is blocked or essentially blocked, or in which'only the by-pass line is opened 'up for the passage of the cooling air while the interior of the cylinder cooling is permitted to flow partially through the illjZfiIiOIlQf the;

cooling jacket and partially through thebypassline and;

(c) To an open position for full loadin which the cooling air is able to flow with full intensity through the cooling jacket whilethe by-pass; line is shut olt or essentially shut off. 7

Referring now to. the drawings, wherein like reference numerals are used throughout the various views to desig nae like parts, and more particularly to Figure 1, reference numeral 10 designates the cylinders which are surrounded by a cooling jacket 11 each. The cooling air is conducted to. they engine on one; side thereof through a collective channel or inlet duct 12, and may be discharged, on the other side. of the engine, through a plurality of discharge channels or outlet conduits 13 directly intov the external atmosphere, or may be discharged also through a single. collective discharge channel.

The. interior of the cooling jackets are each in communication with the inlet channel 12 through an apertrue 15 and with: the discharge channels 13 through an aperture 16 In order to minimize resistance to fiow, and thereby reduce flow losses, the inlet 115 and outlet lines 113 leading intov and from the interior of the cooling jackets 14 may be. formed nozzle-shaped or venturi-like as. shown in Figures 4 and 5. i Intermediate spacesv or channels 19 are formed between the cooling jackets 11 of adjacent cylinders. The intermediate spaces or channels '19 which form by-pass channels or ducts are. in. communication with the inlet channel 12 through apertures 28 and with the discharge channels "13' through. apertures 29. Cut-01f valve or control members 30. are, provided which are arranged in such a manner as 'to control the apertures 29 and "discharge channels 13. The. cut-ofi valve members 30. arefadjustable to at. least three. positions 30, 30" and 30.

Ifthe engine starting condition and is to be warmed up, then the valve members 30 are adjusted to the posi tion 30' as indicated in the. drawing in phantom lines. In that position of the valvemember the interior of each of the'c'ooling jackets 14 is connected with a. respective one of the intermediate spaces or channels 19 which serve as by-pass or short-circuit lines, while at the same time the interior of each cooling jacket 14 is.blocked or shutoff inthe direction ofthe. discharge lines 13. As a result thereof the cooling air can'circulate essentially only between. the interior 14; offthe. cooling jackets and the intermediate spaces 1'9,as shown by the arrows indicated in the drawing in dotted lines withoutpermitting the passage orfiow of an effective cooling air stream through the cooling jacket spaces 14. "Such circulation tends to equalize the temperature within, the difierent parts thereby eliminating any hot or cold spots.

In case of'partial-load conditions, the contr'olor. cut-off valves are adjusted to the positions Sfithereof, shown in the drawing in full lines, so that the cooling air may .fiow out oi the inlet line 12 through the interior of the cooling jackets 14 as well 'as through the by-passl'ines formed by intermediate spaces 19. into the discharge lines 13 of the cooling system. Consequently, only a part of the cooling air will flow past the cylinders 10 and will,therefore, only exert a moderate cooling effect on the cylinders.

In case of full load, the cut-off orcontrol valves are ad'- justed to the position 30", shown in the drawing also in phantom lines, so that all of the cooling air flowing through the inletline it can reach the discharge -lines 1 3 only after flowing past the cylinders through thecooling jacket spaces 14 and thereby providing a maximum cool ing effect. r

' The flow of air in the partial-load position ofthe .control valve members isshown'in the drawing by. the carrows in full line, in which thecooling air-flowsithrough 4 the cooling jackets 14 and the intermediate spaces 19. Of course, in the full-load position of the control valve members no air flows through the intermediate spaces or by-pass channels 19.

In the embodiment according to Figure 2, symmetrically arranged control valves 31, such as butterfly valves, are provided which;control' the discharge apertures 16 of the cooling jacket spaces 14 and the discharge apertures 29 0f the intermediate spaces 19, again forming by-pass or short-circuit lines,.in a. manner similar to that described in connection with Figure 1.

In this embodiment, the position assumed by the control valve members 31'during warm-up of the engine is again, designated by referencenumeral 31, the position thereof during partial-load conditions by reference numeral 31, and the position thereof during full load with reference numeral 31". The circulatory flow of the air during warmupr of the engine when the valve members are in position31 is again shown by'the arrows in dotted line, while the flow of air in the partialand full load conditions is shown by the arrows in full lines.

The embodiment according to Figure 3 distinguishes itself from Figure 2 essentially by the fact that the intermediate spaces 19: forming the by-pass or short-circuit lines arenot connected with the cooling jacket spaces in the. warm-up. position 3 1 of the control valve member butare connected with the discharge lines 13. Otherwise, theoperation is the same asin. connection with the aforedescribed; embodiments;

The embodiment according to Figure 4 distinguishes itself fromthat of Figures 1 tov '3 essentially by the fact thatqthecontrolcvalve members 30 are arranged at the entrance to the cooling jacket 14 and the intermediate air channels. 19 whereby, in the warmup position 31 of the control valve member 31, .no. cooling air circulates through the cooling jacket 14. Otherwise, the operation is the .same .as in the embodiment according to Figure 3.

In the. warm-up position 31 of the valve members the flow: of coolingv air is again indicated. by the arrows in dottedlines. In the partial-load position of the valve members the-flow of air takes place through both cylinder jackets 14 and by-pass spaces 19 and is, therefore, indicated by' both the arrows both in full lines and dotted lines, while in the full-load position the flow of cooling air ispindicated only by the arrows in'full lines.

a The adjustment or controlzvalve members 30 or 31 respectively are appropriately connected with each other inv a given engine and are adjustable in particular manually by a common connecting rod 41 as shown in Figure 5. However, they may also be connected, for example, with theadjustment member that controls the output of the engine, such as with the throttle valve 42, the adjusting member .43 for the fuel injection pump 44, the gas pedal linkageorthe like as shown in Figures. 7 and '8:. If the control valve members 30 and 31 are connected with the particular adjustment member that controls the output of the engine, this may be done in such a way that in the idling position of the engine-output control -member- :theadjustment or control valves 30 and 13 are adjusted automatically to the position indicated by reference numerals '30 and'31', in the partial-load position of the engine-outputcontrol member to the position indicated by reference numerals 30 and 31, and during full load position'of the engineoutput control member to the position indicated by reference numerals 30 and 31". However, his more appropriate to effect adjustment of the control valves 30 and 31 directly depending on the engine, temperature. by means of a thermostat 45 which is exposed to' .the engine temperature as shown in Figure 6.

While in the drawing only three positions are shown, it is understood thatinstead of a three-position valve the valve may also be, continuously adjustable between the. two-end positions h r of, .i, e, o ha aninfi number of positions .between-rtheend positi ns: th reof designated .hereinabove by primed and double-primed reference numerals.

I claim: 7 p p 1. A cooling system for air-cooled internal combustion engines comprising a plurality of engine cylinders mounted next to each other, one cooling jacket substantially enclosing each of said cylinders but spaced there from to form a cooling channel around the cylinder, each of said jackets being provided with inlet and outlet openings at opposite sides thereof, the jackets of adjacent cylinders being spaced from each other so as to form an intermediate air channel therebetween, said intermediate air channel being provided with inlet and outlet openings, and means including a common adjustment valve member for simultaneously controlling the passage of air through a respective jacket and intermediate air channel.

2. A cooling system for air-cooled internal combustion engines comprising a plurality ofengine cylinders mounted next to each other, cooling jackets substantially enclosing said cylinders but spaced therefrom to form cooling channels around saidcylinders, each of said jackets being provided with inlet and outlet openings at opposite sides thereof, the jackets of adjacent cylinders being spaced from each other so as to form an intermediate air channel, said intermediate air channel being provided with inlet and outlet openings, and means including a single adjustment valve member for simultaneously controlling one of said openings of each of said. jacket and intermediate channel to thereby control passage of air through said jacket and through said intermediate air channel.

3. A cooling system for air-cooled internal combustion engines comprising a plurality of engine cylinders mounted next to each other, cooling jackets substantially enclosing said cylinders but spaced therefrom to form cooling channels around said cylinders, each of said jackets being provided with inlet and outlet openings at opposite sides thereof, the jackets of adjacent cylinders being spaced from each other so as to form an intermediate air channel therebetween, said intermediate air channels being provided with inlet and outlet openings, and means including a single valve member for cooperating with the openings of said jackets and said intermediate channels to simultaneously control the passage of air through said jackets and through said intermediate air channels.

4. The cooling system for air-cooled internal combustion engines according to claim 3, wherein each of said valve members has three positions corresponding to warm-up, partial-load and full-load conditions of the engine.

5. The cooling system for air-cooled internal cornbustion engines according to claim 4, wherein all of said valve members are manually controllable in unison.

6. The cooling system for air-cooled internal combustion engines according to claim 4, further comprising thermostatic means in the engine and responsive to the temperature thereof for controlling all of said valve members.

7. The cooling system for air-cooled internal combustion engines with means for adjusting the output thereof according to claim 4, further comprising means connected to the engine output adjusting means for automatically adjusting all of said valve members depending on the position thereof.

8. A cooling system for air-cooled internal combustion engines comprising a plurality of engine cylinders mounted next to each other, cooling jackets substantially enclosing said cylinders but spaced therefrom to form cooling channels around said cylinders, each of said jackets being provided with inlet and outlet openings at opposite sides thereof, the jackets of adjacent cylinders being spaced from each other so as to form an intermediate air channel, said intermediate air channels being the outlet opening of each of said jackets and of said intermediate air channels to thereby control the passage of air through said jackets and through said intermediate air channels.

9. A cooling system for air-cooled internal combus tion engines comprising a plurality of engine cylinders mounted next to each other, cooling jackets substantially v enclosing said cylinders but spaced therefrom to form cooling channels around said cylinders, each of said jackets being provided with inlet and outlet openings at opposite sides thereof, the jackets of adjacent cylinders being spaced from each other so as to form an intermediate air channel, said intermediate air channels being provided with inlet and outlet openings, and means including a single valve member for controlling the outlet openings of associated jackets and intermediate channels to simultaneously control the passage of air through said jackets and through said intermediate air channels.

10. The cooling system for air-cooled internal combustion engines according to claim 9, wherein each valve member has three positions; namely one position for engine warm-up in which the flow of cooling air through the jacket into the outlet opening is blocked, a second position in which part of the cooling air flows through the jacket and another part through the intermediate air channel, and a third position in which flow of the cooling air through the intermediate space is blocked.

11. A cooling system for air-cooled internal combustion engines with inlet means and outlet means for the cooling air comprising a plurality of engine cylinders mounted next to each other, cooling jackets substantially enclosing said cylinders but spaced therefrom to form cooling channels around said cylinders, each of said jackets being provided with inlet and outlet openings at opposite sides thereof, the jackets of adjacent cylinders being spaced from each other so as to form an intermediate air channel, said intermediate air channels being provided with inlet and outlet openings, and means including a single valve member for one of each inlet and outlet openings or a cooperating jacket and intermediate channel to simultaneously control the passage of air through said jacket and through said intermediate air channel, each valve member having at least three positions, namely one in which the interior space of a jacket is connected with a corresponding intermediate air channel While essentially blocking the flow of the cooling air through said outlet means, a second one in which only partial amounts of the cooling air may flow through said interior 'space and said corresponding intermediate air channel, and a third one in which all of the cooling air is permitted to flow through said interior space while essentially blocking the flow thereof through said intermediate air channel.

12. The cooling system for internal combustion engines, according to claim 11, wherein each valve member has an infinite number of positions intermediate said first and third position. v

13. The cooling system for internal combustion engines according to claim 12, comprising means for simultaneously adjusting all of said valve members.

14. The coo-ling system for internal combustion engine according to claim 13, wherein said last-mentioned means includes a thermostat responsive to the temperature of the engine.

15. The cooling system for internal combustion engines according to claim 13, wherein each engine has an adjusting member for adjusting the engine output, and wherein said last-mentioned means is connected to said engine output adjusting member.

16. A cooling system forair-cooled internal combustion engines comprising a plurality of engine cylinders mounted next to each other, cooling jackets substantiallywo ha n ls ar und Said y in rs cas f id, jacke s ein prov ded, wit n t and, cut et p ni gs at ppos e sides he o heiacket of dia n 'cy n t being spaced from each other so as to form? an interm diat a r hann lt id. int me iat a channe being provided With inlet, and outlet openings and means including a single valve member. for one of each inlet and outlet openings of a cooperating jacket and intermediate channel tov simultaneously control the passage of air through said jacket and through said intermediate air channel, each, valvemember having at least. three positions namely one in which the passage of cooling air through the jacket is essentially blocked While rendered free through the intermediate air channel, a second one inwhich a part of the cooling air is permitted to flow in part through, said jacket and in part through said intermediate space, and a third one in which the passage of cooling air through said intermediate channel is essentially blocked while rendered free through said jacket.

17. A cooling system for air-cooled internal combustion engines according to claim 9, wherein said inlet and outlet openings totand from said cooling jacket are venturi shaped, the outlet opening from said cooling jacket outlet openings to and' from said cooling jacket are noz zle shaped, the outlet opening from said cooling jacket being in communication with the outlet opening from said intermediate air channel, said outlet openings being arranged perpendicularly to each other, said valve member being pivotally arranged at the intersection of said ou l open s and h n e fa m of a butterfly valve o rna y ening and l inasaid o t n n s- 19. A cooling system for, air-cooled internal combustion engines according to claim 9, wherein said inlet and outlet openings, to and from said cooling jacket are venu h p d. the. ut et pinn rom a d l ng Jacket.

be arr n e adja sn tq the o tl t Opening of s d intermediate channel, said valve member being in the form of a butterfly valve arranged between said openings for alternately opening and closing said outlet, openings.

N e rence i ed- 

